The Biostatistics portion of Core A is responsible for providing the essential program-wide expertise in experimental analysis and design, data acquisition, editing and management, data analysis, and results interpretation. It will provide the capabilities for, among other things, developing robust facilities for acquiring and managing project data, ensuring the integrity of the acquired data, developing procedures for estimating parameters of interest, assessing covariate significance and model appropriateness, integrating information from the various projects into a consistent whole, and investigating and comparing alternative approaches to data analysis and results interpretation.